As a technology for efficiently utilizing regenerative energy supplied from an alternating current motor to inverters, a current division controller which extracts regenerative energy inconvertible into power supply from all regenerative energy and accumulates the extracted regenerative energy in other power supply has been proposed. At the time of powering, power is supplied from the other power supply (for example, see Patent Reference No. 1).    Patent Reference No. 1: JP-A-2002-291103 (pp. 7, FIG. 1)